Gestational Diabetes Mellitus
Conditions
Brief summary
The study evaluates whether the New Nordic Diet, compared to routine care, will improve glucose control, among women developing gestational diabetes mellitus during pregnancy. Originally, a 10 wk intervention with qualified counseling on New Nordic Diet was planned, and effects on glycosylated haemoglobin A (HbA1c) at gestational age 37 weeks was planned as main outcome. Recruitment started in spring 2020 but had to be halted due to covid-19. Instead, we now conduct a more comprehensive version of the study, with a more intensive intervention consisting of distributed food bags plus dietary counselling for two weeks, and with continuous glucose monitoring during these two weeks to measure main outcome. This is more sensitive to small changes than is HbA1c. With this shorter and more intensive intervention we believe we can address our original hypothesis yet adjust to impacts of the covid-19 situation on the population and health care system.
Detailed description
Gestational diabetes mellitus (GDM) is associated with severe adverse outcomes for mother and newborn. Recently introduced Swedish guidelines on GDM diagnosis will at least double the prevalence of diagnosed women. The first line of treatment in GDM is diet and exercise treatment. Even so, there is a recognized knowledge gap as to what diet treatment is optimal. In routine care today, diagnosed women are provided by midwife with the same diet advice as patients with diabetes type 2 and these are broad and general. Only rarely are the diet advice provided by a dietician. In nutrition research, most evidence for health benefits of a diet has been demonstrated for the Mediterranean diet. Further, the New Nordic Diet (NND) was recently developed to mimic the Mediterranean diet yet builds on foods grown in the Nordic climate, thus focusing on gastronomical potential and sustainability. Interestingly, a diet intake in line with NND among Norwegian mothers was associated with lower risk for excessive pregnancy weight gain. In addition, associations have been shown between NND and lower risk for cardiovascular disease, obesity, inflammatory risk markers, serum lipids, colorectal cancer and total mortality. Hence, it seems likely that diet treatment with NND to women with GDM would be superior to routine care, but this has never been investigated. The main aim of the randomized controlled trial Intervention with new Nordic DIet in women with GestatiOnal diabetes mellitus (iNDIGO) is to test if the NND compared with usual care will improve glucose control in women with GDM. The iNDIGO study is a randomized parallel, single-blinded, controlled trial. In total, 50 women diagnosed with GDM are recruited and randomized to receive either a NND (intervention) or usual care (control) for 14 days. Participants receive a two-week menu and provided with food bags containing ingredients for dishes and foods to be used. Primary outcome is glycemic control (specifically time in target) measured using continuous glucose monitoring. Compliance to the dietary intervention will be tested using known dietary biomarkers and adherence questionnaires. Maternal socio-demographic and clinical data, biological samples, dietary intake and physical activity will be collected at enrollment and at the end of intervention (30-32 weeks' gestation).
Interventions
BEHAVIORALNew Nordic Diet
The New Nordic Diet conforms with the Nordic Nutrition Recommendations and incorporates environmental sustainability and planetary health. It includes rapeseed oil, whole grain bread, wild fish, seafood and game, potatoes, root vegetables, cabbages, Nordic fruits and berries. A two-week menu including all daily meals has been created to ensure dietary goals of the New Nordic Diet intervention: fish and shellfish intake ≥ 3 times/w (fatty fish at least once per week), ≥ 500 g fruit, berries, vegetables and legumes daily (legumes as main protein source at least twice per week), whole-grain cereal products, rapeseed oil for cooking/dressing and three table spoons of nuts and seeds per day.
OTHERControl
The control women receive diet advice according to usual care, which may be a short meeting with the regular midwife or a short meeting with a dietician. From the study, they will receive a gift certificate that can be used in grocery stores.
Sponsors
Swedish Council for Working Life and Social Research
Göteborg University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
DOUBLE (Investigator, Outcomes Assessor)
Masking description
Outcome is percentage of time in target of blood glucose values, measured with continuous glucose monitoring. The device will be masked for participants. Still, because the trial is a diet intervention, participants will know their group status. However, initial data reaching the Investigators will not have the code broken.
Intervention model description
Parallel Assignment
Eligibility
Sex/Gender
FEMALE
Age
18 Years to 50 Years
Healthy volunteers
No
Inclusion criteria
* pregnant women with diagnosis of gestational diabetes in pregnancy wks 24-28.
Exclusion criteria
* multiple pregnancies * not understanding/able to read Swedish or English * unwilling to follow a dietary intervention * manifest diabetes
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Time in Target at gestational week 32 | At week 32 of pregnancy | Percentage of time in target (TIT) range 3.5-7.8 mmol/L measured with continuous glucose monitoring |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Incidence of pregnancy-induced hypertension | Up to delivery | Diagnosis of pregnancy-induced hypertension |
| Incidence of pre-eclampsia | Up to delivery | Diagnosis of pre-eclampsia |
| Prevalence of use of insulin/Metformin treatment | Up to delivery | Decision to put woman on medication for the gestational diabetes, such as metformin or insulin |
| Incidence of preterm delivery | Up to 37 completed weeks | Delivery before 37 completed weeks |
| Incidence of Caesarean sections | Up to delivery | Delivery by caesarean sections |
| Health-related quality of life | Up to 1 year postpartum | Health-related quality of life, calculated from questionnaire information from RAND-36 |
| Incidence of LGA | At delivery | Large-for-gestational age born infant |
| Pregnancy weight gain | Pre-pregnant weight up to delivery | Weight gain during pregnancy from self-reported pre-pregnancy weight until delivery |
| Apgar scores measurements | At delivery | Apgar scores measured at 1, 5 and 10 minutes after delivery |
| Additional measurements from continuous glucose monitoring at wk 32 | At gestational week 32 | mean glucose, CV, SD, MAGE, % time with values \>7.8 mmol/L, % time with values \<3.5 mmol/L, glucose in different time periods, and AUC |
| Additional measurements from continuous glucose monitoring at wk 36 | At gestational week 36 | mean glucose, CV, SD, MAGE, % time with values \>7.8 mmol/L, % time with values \<3.5 mmol/L, glucose in different time periods, and AUC |
| Incidence of macrosomia | At delivery | Diagnosis of macrosomia in newborn infant |
| Nutritional status | During pregnancy | Nutritional status (vitamins and minerals) of mother during pregnancy |
| Diet quality measuremen¨t | Up to delivery | Diet intake quality of mother during pregnancy |
| Incidence of shoulder displacement | At delivery | Shoulder displacement of newborn infant |
Countries
Sweden
Outcome results
None listed